The NFL Network first reported his decision this week and Martz told the Chicago Sun-Times, “It's time.” He did not return a message left Tuesday.

The architect of “The Greatest Show on Turf” as offensive co-ordinator and head coach of the Rams, Martz spent the past two seasons as the Chicago Bears' offensive co-ordinator. He had an expiring contract and left after what were described as philosophical differences.

The Bears finished 8-8 after season-ending injuries to quarterback Jay Cutler and running back Matt Forte. Martz is best remembered for his time in St. Louis, where he helped the 1999 team win a championship as offensive co-ordinator under Dick Vermeil and the 2001 team get back to the Super Bowl as head coach. Bears coach Lovie Smith was his defensive co-ordinator.